diff --git a/modules/logging/netwriter.go b/modules/logging/netwriter.go
index 5a6cf3947..954a09b2c 100644
--- a/modules/logging/netwriter.go
+++ b/modules/logging/netwriter.go
@@ -40,6 +40,11 @@ type NetWriter struct {
// The timeout to wait while connecting to the socket.
DialTimeout caddy.Duration `json:"dial_timeout,omitempty"`
+ // If enabled, allow connections errors when first opening the
+ // writer. The error and subsequent log entries will be reported
+ // to stderr instead until a connection can be re-established.
+ SoftStart bool `json:"soft_start,omitempty"`
+
addr caddy.NetworkAddress
}
@@ -92,7 +97,9 @@ func (nw NetWriter) OpenWriter() (io.WriteCloser, error) {
}
conn, err := reconn.dial()
if err != nil {
- return nil, err
+ // don't block config load if remote is down or some other external problem;
+ // we can dump logs to stderr for now (see issue #5520)
+ fmt.Fprintf(os.Stderr, "[ERROR] net log writer failed to connect: %v (will retry connection and print errors here in the meantime)\n", err)
}
reconn.connMu.Lock()
reconn.Conn = conn
@@ -104,6 +111,7 @@ func (nw NetWriter) OpenWriter() (io.WriteCloser, error) {
//
// net
{
// dial_timeout
+// soft_start
// }
func (nw *NetWriter) UnmarshalCaddyfile(d *caddyfile.Dispenser) error {
for d.Next() {
@@ -128,6 +136,12 @@ func (nw *NetWriter) UnmarshalCaddyfile(d *caddyfile.Dispenser) error {
return d.ArgErr()
}
nw.DialTimeout = caddy.Duration(timeout)
+
+ case "soft_start":
+ if d.NextArg() {
+ return d.ArgErr()
+ }
+ nw.SoftStart = true
}
}
}
@@ -151,8 +165,10 @@ func (reconn *redialerConn) Write(b []byte) (n int, err error) {
reconn.connMu.RLock()
conn := reconn.Conn
reconn.connMu.RUnlock()
- if n, err = conn.Write(b); err == nil {
- return
+ if conn != nil {
+ if n, err = conn.Write(b); err == nil {
+ return
+ }
}
// problem with the connection - lock it and try to fix it
@@ -161,8 +177,10 @@ func (reconn *redialerConn) Write(b []byte) (n int, err error) {
// if multiple concurrent writes failed on the same broken conn, then
// one of them might have already re-dialed by now; try writing again
- if n, err = reconn.Conn.Write(b); err == nil {
- return
+ if reconn.Conn != nil {
+ if n, err = reconn.Conn.Write(b); err == nil {
+ return
+ }
}
// there's still a problem, so try to re-attempt dialing the socket
@@ -178,7 +196,9 @@ func (reconn *redialerConn) Write(b []byte) (n int, err error) {
return
}
if n, err = conn2.Write(b); err == nil {
- reconn.Conn.Close()
+ if reconn.Conn != nil {
+ reconn.Conn.Close()
+ }
reconn.Conn = conn2
}
} else {